1nsane

I'm looking to build a touring Bike and thus far I have narrowed it down to one bike, the Surly Disc Trucker. So currently i'm in the process if specing the bike, however I have a few questions regarding some of the braking components. I dont have any wheels either, so I can either Centerlock or 6-bolt.

I understand that Centerlock is Shimano's system, while 6-bolt is used by all other manufacturers. I know that centerlock requires either a proprietary tool or the BB tool, vs the use of 6 bolts torx or hex. As far as I'm considered from a ease of installation pov, they are both the same. If anything 6-bolt would be preferred since I could combine that with a HEX bolts, a tool that you will carry anyway.

Components I would like to use:

Avid BB7's MTB or Road,
Tektro RL520 Brake levers
6 bolt or centerlock hub's

I was focused on centerlock, however recent information has pointed me towards an BB7 Brake kit, which comes with both front and rear caliper's and 6-bolt Brake Disc's. THis kit would be around 60 euro's less then buying separate Calipers and centerlock disc's.

As for Road vs MTB, my preference would be MTB. Since they are black instead of silver, this would match the rest of the bike better. Additionally the MTB kit is another 5-10% cheaper. However this argument isn't leading, i can overcome a price difference of 5-10 euro and deal with silver.

So here are the questions.

1. Is any frame compatible with Centerlock or 6-bolt rotor's? I did some google and forums searches, where people stated they had some clearance issues. This has gotten me somewhat worried. So is Disc Trucker compatible with both?

2. Avid BB7's are they compatible with both Centerlock and 6-bolt? Or just one of the 2.

3a. Avid BB7's come in both Road and MTB versions, my google/forum searches have indicated that the MTB comes with a larger pull. However, most topics were a couple of years old already. So is this still the case?

3b. To what extend limits this the choice of brake levers, I have understood that because of the longer pull of the MTB version, combined with RL520's the brakes can feel sloppy, due to the longer travel.

4. I can use either TORX or HEX on 6 bolt rotor's?

5. Any other reason why I should centerlock over 6-bolt and vice versa?

Thanks in advance

Abu Mahendra

1. Rotors mount on hubs, not frames. Therefore it does not make sense to ask whether a frame is compatible with six-bolt or center-lock. The question is whether the hubs are six-bolt or centerlock. Rotor clearance is a separate matter which is indeed dependant on the frame/fork. Two separate issues, compatibility and clearence.

2. Disk brake calipers don't know, don't care whether the rotors are mounted on the hubs via centerlock, or via six-bolt.

3a. Road vs MTB brakes have different cable pull, therefore different types of brake levers. That is still the case today.

3b. It limits lever choice to the extent that Road calipers ought to be mated to Road levers, and MTB brakes to MTB levers.

saddlesores

what hubs are you using?

centerlock rotors can not be used on 6-bolt hubs, but 6-bolt rotors
can be used on centerlock hubs with an extra adapter.

if my 6-bolt rotors are damaged beyond repair by airline staff,
i can always find a spare......worst case, buy a junk chinese
mtb at the local market for $20...strip for parts.

1nsane

Dont have any hubs yet, I can go either way.

Trevtassie

I'd go 6 bolt and TRP Spyres. 6 bolt because you just need a mini tool to remove for transport. Spyres because both pads move and thus don't need constant adjustment like the BB7. Or the TRP cable over hydraulic. I have BB7 and they suck in mountainous terrain with all the adjustment needed of used a lot.

seeker333

FYI, BB7 Road brake calipers are available in black or silver finish. When I built my Disc Trucker in 2013, BB7 Roads were available only in silver, so I spray-painted them black (all black component color scheme). I don't recommend painting as it takes forever for the paint to harden, and DIY is never as tough and pretty as factory paint.

The distinguishing feature between BB7 Mtb and Road brakes is the amount of cable pull required to properly actuate brake. Mtb requires more cable pull than Road (the length of cable movement or travel, not force), thus so-called "long pull" and "short pull" brakes. You must use LP levers with LP calipers and SP levers with SP calipers, or braking will be compromised. Typical road bike brake-shifters "brifters" (i.e. Shimano 105/Ultegra/DA) won't work right with BB7 Mtb calipers.

Assuming you are content with bar-end or downtube (DT) shifters, BB7 Mtb calipers and RL520 levers will work fine. RL520 levers (and their slightly fancier Cane Creek Drop V clone) fit the hand a little differently than brifters WRT lever operation. Bear in mind that once you commit to BB7 Mtb calipers, if you later decide to move from bar-end or DT shifters to brifters, then you'll need to buy new compatible short-cable-pull road calipers, or cable pull adapters (Problem Solver Travel Agent), which I don't recommend as their small cable bending radius hastens brake cable failure.

Handlebar type is a big factor here - Mtb calipers & levers are required for Mtb style "flat" bars, and Road calipers & levers are required for Road style "drop" bars (AFAIK, RL520/CCDV are the only long pull drop bar levers available). So decide first which type of handlebar you commit to, as this ultimately determines levers, shifters, brifters and brake calipers required.

Answers by the numbers:

1. Disc Trucker is compatible with any disc brake caliper and rotor, provided you can mount directly or with adapter to 51mm International Standard brake mount, and limit rotor diameter to 160mm. You can use 6 bolt or centerlock rotor and hub, it does not matter as far as the Surly frameset is concerned. These specs also apply to many frames and forks (51mm IS + 160mm rotor), although newer Post and Flat mounts can be found, and many mountain bikes accept rotors up to 8" (203mm) diameter.

2. BB7 (or any other brake caliper) can work with either 6 bolt or compatible centerlock rotor. BB7s come with 6-bolt rotor so centerlock would require additional expense of another rotor (or a rotor adapter). There are some issues with rotor width and caliper compatibility, so stick to the BB7-included 6 bolt rotor if you wish to avoid compatibility issues.

3a & b. See discussion above.

4. Yes.

5. Centerlock is attractive to tourists because it permits slightly easier rotor removal prior to air or motor vehicle travel, so that the rotors will not get bent. Rotors tend to get bent more from handling mishaps rather than from actual bicycling. I've bent a rotor on two occasions, both while bike was parked and never from actually riding the bike. If you don't expect to be schlepping your bike onto a bus/train/plane often, then ease of removing rotor is less of an issue, and sticking to 6-bolt makes more sense.

Bent rotors are the bane of disc brake users. A properly adjusted disc brake has very little accommodation for rotor runout (lateral deflection, i.e. "bent" rotor). A bent rotor forces you to back off brake pad position so that it won't rub, which in turn makes the brake perform poorly - this is analogous to having to back off brake pads on a rim-braked bike with wheels that are not "true". When rotors are bent, the bend is often so slight that many users cannot discern the problem, other than the fact that their brake pads rub the rotor and they have to adjust them frequently, which seemingly never ends. These users may interpret the experience as "high maintenance brake" when in fact the root cause is simply a bent rotor. Fix the rotor (yes, you can true them) and the brake will work like a champ. Millions of dollars have likely been spent on replacement brake calipers when the only solution needed was to correct rotor runout.

It sounds like you are content with 6-bolt. This is fine, keep it simple and cheap.

Rob_E

Not aware of any frame issues. Ideally neither should require a different clearance than the other. I ride a Surly Troll and have centerlock on the rear wheel and 6-bolt on the front. No issues. Can't imagine it'd be different with Disc Trucker.

Yes. BB7s front and rear, originally. One Centerlock, one 6-bolt. Now using TRP Spykes with the same combination.

I just bought my brakes and levers as a set. I think they were long-pull, but I don't remember.

Don't know. I use the Torx bolts they came with. My multi-tool has what I need, I think.

I feel like there is a wider selection for 6-bolt discs. But I find Centerlock much quicker to put on and remove. But then it's not like you remove them that often. I take mine off for shipping a couple of times a year, and I still wouldn't consider the ease of use of Centerlock to be a huge issue. Still, it's weird having one of each, and my rear hub only comes with Centerlock, so I wish I had gone that way in front as well.

When touring, I'd probably want to have the ability to remove the disc in a pinch. Centerbolt requires an extra tool, whereas you may find a multi-tool with the head for 6-bolt.

Tourist in MSN

I do not know if you can use mountain bike disc brakes with the RL 520 brake levers, send an e-mail to Tektro and ask them for advice.

seeker333

Tektro RL520 are intended for long-pull mountain brakes. They are std equipment on a Surly DT Complete:

https://surlybikes.com/bikes/disc_trucker/bike_specs

https://www.tektro.com/products.php?p=71

So are these slightly nicer Cane Creek clones (which may be discontinued), thus the name Drop V (as in drop bars + vee brakes):

https://www.amazon.com/Cane-Creek-Ca.../dp/B001GSQO4G

Brian25

FYI: As an ex bicycle store owner, I have been really unimpressed with the stopping ability of mechanical disk brakes. I do not know how much you and your loaded touring bike will weigh once it is outfitted and if you have any intention of riding it down any steep hills? I was reading about a guy touring with his bike, going down Sonora pass in California and he had the unfortunate situation where he was squeezing his brake levers as hard as he could on his bike with mechanical disk brakes. The bike continued to accelerate, he was unable to negotiate a turn because of his excessive speed and ended up crashing. (breaking his hip) Just a warning to you; Do not get too caught up in technology where you are apt to get hurt. If you plan to carry a big load and really want disk brakes, go out to your lbs and try a bike with hydraulic brakes, I think that you will see what I mean.

Tourist in MSN

Thanks. I knew they were for mountain V brakes, but with discs I only have road brake experience so I did not want to guess when I gave my answer.

Trevtassie

That sounds like he cooked his brakes. Easy to do with any kind of disc brake, by dumping heat into the discs faster than it can dissipate or that the pads can cope with ie metallic pads cope with heat better. Effectively the heat causes the coefficient of friction to drop so low the pads no longer drag on the discs, ie you don't slow down, no matter how hard you squeeze the brakes, of any type.
Hydraulics have definite advantages, better modulation and no adjustment needed, but they won't inherently stop you any better once they are cooked.

Trevtassie

Oh yeah, if you are going MTB cable pull then you need TRP Spykes not Spyres https://www.ebay.com/p/TRP-SPYKE-All...ack/1630958207

djb

Dragging ones brakes to an extent that over heats them can produce this effect no matter the system, rim brakes or disc, mechanical or hydraulic.

Proper braking technique will greatly reduce the risk odd this happening, along with reasonable observation of how the brakes are responding.

djb

I don't have any personal experience with spyres, but I can say that my mountainous terrain experience with bb7s has had pretty minimal adjustments needed.
Caveat is that I'm a light guy and I generally never drag the brakes, or at least as little as possible.

geoffs

We use TRP Spyres on our loaded tandem and they pull up fine. Noticeably better than BB7's. Spyres also give much more clearance for installing pannier racks if the disc mount is on the seat stay.

Tourist in MSN

After seeing some folks disagreed with you, I just thought I would say that I almost completely agree with this. But for a touring bike I would not want to have to try to fix hydraulics while on a tour.

I have a bike with one disc and one rim brake, my rim brake out-performs when dry. The only time the disc is better is in rain. My rim brake is a V brake with Koolstop Salmon pads, the disc brake is TRP Spyre with TRP pads and rotor.

I am considering switching the disc brake to resin pads to see if that improves it.

veganbikes

+1 on the Spyres or Spykes (if you are using long pull levers)

I would go with Spyres and SRAM S-500 levers personally as those are extremely comfortable ergonomic road levers. If not those levers then the TRP RRL levers which I haven't had much time on but I liked them on feel. They can also be had in a drillium gum hood configuration which is a nice look.

https://www.sram.com/sram/road/produ...pwum2131vw99rh

https://www.trpcycling.com/product/rrl-sr/

As far as 6 bolt vs. centerlock. 6-bolt is certainly easier to find but the rotors typically use a T-25 torx key (which is good to have anyway) so you don't strip the bolt. It does take longer to install but works just fine. However Centerlock is not hard to find these days either many top quality hub makers have centerlock hubs (and some will do both) many rotor manufacturers also do centerlock so it is not hard to find and removal is really easy and uses a standard cassette lockring tool. Me personally on a touring bike I am world traveling with I would probably stick with 6-bolt but for more continental adventures or nearer to well developed cities, I might consider centerlock especially since I could go with XTR IceTech rotors which just look nice to me at least.

fietsbob

I have a Schmidt Delux hub dynamo, center-loc disc, and a 6 bolt disc and an adapter (QBP) between the 2, &

BB7 Mtn, caliper, Speed Dial MTB levers on Trekking bars.. it was OEM pick on my Bike Friday , all I've changed is the pads.

KoolStop organic perform* better than stock Avid..


* @ my very modest speed , they're quieter..


Advantage; when packing bike, to go in a box to fly somewhere, it can be packed separately, to stay flat..

center loc disc can be removed easily, same spline as the rear cassette lockring




...

1nsane

Thanks everyone for their input, all my questions have been answered.

Looks like ill be going for, Avid BB7's MTB and Tektro RL520 brake levers.
This setup would allow me to swap from drop to flat bars, without having to repurchase brake calipers. As for the centerlock or 6-bolt, seems like there is no real reason to choose one of the other. So 6 bolt it is, since it will be slightly cheaper since Avid offers a BB7 6 bolt combo pack.

3speed

I have both centerlock and six bolt disks on a couple of bikes. I would strongly urge you to avoid centerlock on your touring bike, unless the idea of hauling a big wrench and a specific extra tool around on tour is appealing to you. Six bolt is simple and requires no special tools to remove for packing or replace should you need to. Centerlock is fine if you’re working on the bike in your home shop. For me, it’s the one worry I have on my touring bike when traveling. If my bike gets handled roughly by a baggage handler and my rotor gets bent, I’m f....d. I can replace anything else on the bike easily with my multitool. It’s also much easier to find a six bolt rotor replacement than the centerlock. Commuter or MTB with centerlock is merely an annoyance and maybe ruins your day when something goes wrong. On a touring bike, it could, and likely will in Many parts of the world, ruin your trip.

saddlesores

we're already hauling a 6" crescent and cassette tool for spoke replacements.

fourfa

Shimano's centerlock lockrings use their cassette tool for removal, so if you're already carrying that tool you're good to go. I have a bike that came with DT Swiss hubs, and their centerlock lockrings use the same tool as the bottom bracket - which is easily swapped for the Shimano ones if you like. Just make sure you check it out before leaving on tour.

I think others noted that you can put plain 6-bolt rotors on a centerlock adapter, and have the best of both worlds. Or the worst of both worlds, if you like. I've never had a 6-bolt rotor come loose (seems like everyone knows to use blue loctite on the fixing bolts) but I did have a centerlock lockring loosen up leading to a hellacious rattle until I secured it. Turns out, if you hold down your front brake lever at stop lights and rock forward and back a bit, that motion can encourage the lockring to loosen. No real harm done - the rotor can't do more than just rattle on the splines - and proper torque checks or a dab of loctite will solve it too.